Articulated boat rudders



Aug. 15, 1961 E. w. EASTER 2,996,031

ARTICULATED BOAT RUDDERS Filed July 28, 1955 8 Sheets-Sheet l FIG. I 20 N /29 X 26 27 28 33 2s y 22 m "M 1 a FIG. 2 INVENTOR.

E LMER W EASTER Art-vs.

1961 E. w. EASTER 2,996,031

ARTICULATED BOAT RUDDERS Filed July 28, 1955 8 Sheets-Sheet 2 INVENTOR. ELMER W. EASTER Aug. 15, .1961 E. w. EASTER ARTICULATED BOAT RUDDERS 8 Sheets-Sheet 3 Filed July 28, 1955 INVENTOR. 'ELMER W. EASTER BY 7 WWW M a \2262552,:2;2.525275; Lwa

ATTY-$- Aug. 15, 1961 E. w. EASTER ARTICULATED BOAT RUDDERS 8 Sheets-Sheet. 4

Filed July 28, 1955 INVEN TOR. ELMER W EASTER ATTYS.

Aug. 15, 1961 E. w. EASTER 2,995,031

ARTICULATED BOAT RUDDERS Filed July 28 1955 8 Sheets-Sheet 6 m U- h I LA Bil/g,

Aug. 15, 1961 E. w. EASTER ARTICULATED BOAT RUDDERS 8 Sheets-Sheet '7 Filed July 28, 1955 INVE R ELMER W. STER M MwM/w A TTYS.

Aug. 15, 1961 E. w. EASTER ARTICULATED BOAT RUDDERS 8 Sheets-Sheet 8 Filed July 28, 1955 R .E mm MA EE WW R E M L E ATTY United States Patent.

2,996,031 ARTICULATED BOAT RUDDERS Elmer W. Easter, Pittsburgh, Pa., assignor to Dravo Corporation, Pittsburgh, Pa., a corporation of Pennsylvaura Filed July 28, 1955, Ser. No. 524,915 12 Claims. (Cl. 114-167) This invention is concerned generally with push type tow boats and more specifically with a new type of articulated flanking and steering rudders for increasing the maneuverability of long tows being handled by such boats.

Propeller driven push type tow boats are primarily used for handling long strings of barges on inland rivers. Such boats are also sea going and the rudder constructions herein described are equally applicable to sea going boats. River tow boats frequently handle a string of laden barges which extend as much as a quarter mile or more in front of the boat. The rivers are usually winding with many sharp bends requiring ready maneuverability of the boat and tow to negotiate them. These river boats are now propelled by screw type propellers mounted at the stern of the boat. Such propellers are usually mounted in pairs on the boat and spaced transversely thereof. It is advantageous to mount each propeller within some type of tunnel, one of the well known types being referred to as a Kort nozzle and is illustrated in the drawings.

It is old in the art to mount a rudder, referred to as the steering rudder, aft of the propeller and preferably in alignment therewith longitudinally of the boat. In recent years flanking rudders, mounted forwardly of the propeller and at opposite sides of the propeller shaft, have been added to increase the maneuverability of the boat. The combination of steering and flanking rudders is effective without the propeller tunnel, but the addition thereof measurably increases the flanking rudder effectiveness. These flanking rudders, during straight forward propulsion of the boat are maintained in an inoperative or neutral position. In other 'words they are so disposed as to offer a minimum impediment to forward motion of the boat. With most designs of flanking rudders a toe out forward of about and a toe in aft of the same degree provides a minimum impedance to the flow of water past the rudders and towards the propeller during forward propulsion.

In order to obtain quick response to the steering rudder in the forward end of the forwardly moving tow, the propeller is reversed and the flanking rudders are turned to deflect the forward flow of water from the reversed propeller. The degree of rotation of the flanking rudders from neutral position will of course depend upon the degree of response desired in the forward end of the tow. The maximum degree of rotation from neutral position is about 35 in either direction. This maximum rotation position is referred to as the hard over or hard down position. In this position the aft end of one flanking rudder of each pair of flanking rudders is disposed between the nozzle side walls and in proximity to the adjacent side wall for maximum deflection of the water flowing from the reversed propeller. The other rudder of the pair is rotated a similar amount but in a direction away from its adjacent nozzle side wall. When the rudders of a pair are rotated in the opposite direction from neutral position the relative positions of the trailing ends of the rudders and nozzle side walls are reversed.

An object of the present invention is to increase the effectiveness of the rudders by articulating one or both ends of each rudder so that the articulated portion moves with the body of the rudder and also rotates relative thereto so as to increase the resistance to water flow from the reversed propeller.

Another object of the invention is to provide a novel mechanism for effecting relative rotation between the articulated end portion and body portion of the rudder.

These and other objects will be apparent from the following description and the attached drawings forming a part thereof, in which:

FIG. 1 shows a plan view of a propeller and steering and flanking rudders with the aft end of the flanking rudders articulated, said rudders and propeller being associated with a nozzle shown in horizontal cross section;

FIG. 2 shows a plan view of a propeller and steering and flanking rudders with the forward ends of the flanking rudders articulated and the trailing end of the steering rudder articulated, said rudders and propeller being associated with a nozzle shown in horizontal cross section;

FIG. 3 shows a plan view of a propeller, and an alternate form of articulation of the steering and flanking rudders, associated with a nozzle as in FIG. 2;

FIG. 4 shows a typical side elevation of the articulated flanking rudder, nozzle and propeller and a side elevation of the control for the end portion of rudder shown in FIG. 2;

FIG. 5 shows an enlarged partial plan view of a portion of the nozzle, propeller and articulated flanking rudder of FIG. 3;

FIG. 6 shows a similar enlarged plan view from FIG. 2;

FIG. 7 shows a similar enlarged plan view from FIG. 1;

FIG. 8 shows a plan view of flanking and stern rudders having both ends articulated, said rudders being'associated with a nozzle shown in horizontal cross section;

FIG. 9 shows a side elevation of the rudders of FIG. 8;

FIG. 10 shows in plan view an alternate form of articulated rudders as in FIG. 8; and

FIG. 11 shows in elevation the rudders of FIG. '10.

Referring now to FIGS. 1 and 7 of the drawings showing a longitudinal section through the tunnel herein referred to as the nozzle 1 which is provided with side walls 2 and a bottom plate 3. A propeller 4 of suitable design is driven through the usual propeller shaft 5. A steering rudder post 6 and flanking rudder posts 7 are suspended in any suitable manner (not shown) and have a pivotal connection with the nozzle bottom wall 3. The con struction so far described is conventional and well known in the art so that further description thereof is not deemed necessary. A steering rudder 8, of any suitable design, is mounted upon the steering post 6. The flanking rudder posts 7 are preferably disposed at equal distances on opposite sides of the propeller shaft 5 and the flanking rudders 9 are secured intermediate their ends to the 'posts 7 for concurrent rotation therewith. The trailing end of the flanking rudders 9 are formed of the articulated flaps 10 pivotally mounted on the body portion 9 of the rudder by means of a suitable pivot member such as 11. As shown in full lines on FIG. 1 the flanking rudder body portion and flap are disposed in substantial alignment when the rudder is in neutral or inoperative position. In such neutral position the leading or forward edge of the rudders at opposite sides of the propeller shaft preferably toe out a suitable distance such as 5 and the aft or trailing edge of the rudders toe in a corresponding amount. A steering engine (not shown) of any suitable design provides for concurrent movement in opposite directions from neutral position. The artculated flaps 10 are moved concurrently with the rudder body portion 9 and rotated relative to the rudder body portions 9 by means of a member 12 rigidly connected at one end 13 to flap 10 and slidably connected at its opposite end to nozzle plate 3 by means of pin 14 having a head portion 15 slidable in slot 16 of member 12. The member 12 is disposed between nozzle plate 3 and rudder 9. Intermediate its ends, the plate 12 has an arcuate opening 17 engaged with post 7 so as to move relative thereto as rudder 9 is rotated. Plate 12 and flap 10 rotate about pivot member 11 as rudder 9 moves with steering post 7. As shown in the drawings flap 10 is disposed in an angular relation of about 15 to rudder 9 in hard down position. By modifying the relationship of plate 12 to plate 3 any other desired angular relationship between 9 and 10 may be obtained.

Referring now to FIGS. 2 and 6 of the drawings, the nozzle 20 of conventional design is provided with side walls 21 and a bottom plate 22 extending beyond opposite ends of the side walls. Between the side walls 21 is mounted a propeller 23 of suitable design driven by a propeller shaft 24 extending forward of the propeller. In alignment with the propeller is the steering rudder comprised of the body portion 25 having one end rigidly connected to a steering post 26 suitably mounted on the boat structure and having a bottom pivotal connection with the nozzle bottom plate 22. The free end of the stern rudder body portion 25 is provided with a flap 27 having an articulated connection to the portion 25 by means of a shaft 28. Movement of flap 27 relative to the rudder body portion 25 is provided through the pintle pin 29 slidably mounted in the member 30 pivotally mounted beneath the rudder body portion 25 upon the nozzle bottom wall 22 rearwardly of the post 26 and in alignment therewith. The head of the pintle pin 29 is provided with a transversely disposed portion 31. A transversely disposed member 32 is mounted on the member 28 and rigidly secured to the flap portion 27.

- Links 33 pivotally connect the pintle head portion 31 and the member 32 providing rotation of the flap 27 relative to the steering rudder body portion 25 while moving concurrent therewith. Forwardly of the propeller and at opposite sides of the propeller shaft 24 are mounted the flanking rudders comprising a body portion 36 and articulated flap 37. The body portion 36 is secured intermediate its ends to the rudder post 38 which is suitably mounted on the boat structure and has a pivotal connection with the tunnel bottom plate 22. The flap 37 is pivotally mounted on the forward end of the rudder body portion 36 by means of the shaft 39 and is disposed in alignment with the body portion 36 when the rudder is in neutral or inoperative position as shown in full lines in the drawing. In neutral position the flanking rudders on opposite sides of the propeller shaft normally toe outward and their trailing edges normally toe inward approximately Relative movement between the flap 37 and rudder body portion 36 is provided by the pintle pin 40 having one end pivotally mounted on the shaft 39 and rigidly connected to the flap 37. The opposite end of the pintle pin 40 is slidably connected with a shaft member 41 pivotally mounted on the tunneled bottom wall 22 beneath the rudder 36 in alignment with the rudder posts 38 in a manner similar to FIG. 4. A suitable steering engine (not shown) is mounted on the boat structure and connected with the posts 38 providing concurrent substantially parallel rotation of the rudder body portions 36 about opposite sides of the propeller shaft 24.

Referring now to FIGS. 3 and 5 of the drawings the nozzle 45 is provided with side walls 46 and a bottom wall 47 which extends beyond opposite ends of the side walls. A propeller 48 of suitable design is mounted within the nozzle between the side walls in the usual manner and is driven by the usual shaft 49. A steering rudder is disposed rearwardly of the propeller and in substantial alignment therewith. This rudder comprises a body portion 50 and an articulated flap portion 51. One end of the portion 50 is mounted on a steering post 52 which is suitably supported from the boat structure and has a pivotal connection with the nozzle bottom wall 47. A suitable steering engine (not shown) is provided for rotating the steering post 52 and rudder mounted thereon. The flap portion 51 is pivotally mounted on the stern rudder body portion 50 by any suitable means such as the shaft 53. When the steering rudder is in neutral position, the flap 51 is disposed in alignment therewith as shown in the drawings. Pivotal movement of the flap 51 relative to the body portion 50 is provided by a pintle pin 54 pivotally mounted adjacent one end on the member 53 and rigidly secured to the flap 51. The opposite end of the pintle pin has a slidable connection with a shaft member 55 pivotally mounted upon the nozzle bottom wall 47 beneath the steering rudder body portion 50 and in alignment with the steering post 52 similar to that shown in FIG. 4. Forwardly of the propeller and at opposite sides of the propeller shaft are the flanking rudders, each comprised of the body portion 57 and a flap portion 58. The body portion 57 is mounted intermediate its ends on the rudder post 59 suitably suspended from the boat structure and having a pivotal connection with the nozzle bottom plate 47. The flap 58 is pivotally connected to the rudder body portion by means of the member 60 permitting pivotal movement of the flap relative to the body portion. Movement of the flap relative to the body portion is provided by the lever 61 pivotally mounted on the member 60 and rigidly connected at one end to the flap 58. The lever 61 extends outwardly from the member 60 to one side of the longitudinal center line of the rudder and at its outer end is pivotally connected at 62 to a link 63 which extends toward the post 59 and has a pivotal connection 64 with the nozzle bottom plate 47 at the opposite side of the center line of the rudder so that the flap 58 is in alignment with the rudder body portion 57 when the rudder is in neutral position. As shown in the drawings the rudders on opposite sides of the propeller shaft in neutral position have their forward ends toed out an equal amount which is approximately 5 and the trailing edge of the propellers toe in a corresponding amount.

In FIG. 4 of the drawings is shown a typical side elevation of the articulated flanking rudders and associated portions of the nozzle and propeller. This view also shows in side elevation a typical construction of the pintle pin control for the rudder flap as in FIGS. 2 and 3. The typical body portion 36a of the flanking rudder is mounted intermediate its ends on a steering post 38a of suitable design and having a pivotal connection with the bottom wall 22a of the nozzle. The articulated flap 37a is pivotally connected with the rudder body portion 36a by means of a suitable shaft 39a. Beneath the rudder and pivotally mounted in the nozzle bottom wall 22a is the shaft 41a having an opening extending transversely thereof through which one end of the pintle pin 40 slidably moves. The other end of the pintle pin 40a is rigidly secured to the flap 37a and pivotally connected with the shaft 39a.

Referring now to FIGS. 8 and 9 of the drawings, the three piece articulated flanking and stern rudders are shown with a suitable tunnel or nozzle 70 having side walls 71 and a bottom plate 72. A suitable propeller 73 is disposed within the nozzle and is mounted upon the forwardly extending shaft 74. The stern rudder disposed in substantial alignment with the propeller comprises a forwardly extending portion 75 mounted at one end on post 76 for concurrent movement therewith, an intermediate portion 77 pivotally mounted on rudder post 76 and a flap 78 is pivotally mounted on the aft end of portion 77 by means of the shaft 79. An extension 80 rigid with rudder portion 75 extends aft of post 76 beneath rudder portion 77 in spaced relation thereto. A pintle 81 is pivotally mounted on tunnel bottom plate 72 beneath extension 80 and has an aperture therein to slidably receive the shank of a pintle pin 82 rigidly connected with flap 78. Extension 80 adjacent its aft end has a slotted opening 83 therein disposed longitudinally thereof receiving the head of pin 84. The shank of pin 84 is pivotally connected to a lever '85 having its opposite end secured to pintle 81. I

The flanking rudders shown in pairs on opposite sides of the propeller, comprise the rudder section 86 mounted intermediate its ends on rudder post 87 for concurrent rotation therewith. Pivotally mounted on the forward and aft ends of rudder 86 are the flaps 88 and 89 respectively. Each flap is pivotally connected to the rudder section 86 by shafts 90. The flaps 88 and 89 rotate concurrently with rudder 86 and also relative thereto. Flap control is provided by a link 91 slidably mounted in post 87 and having its opposite ends pivotally connected at 92 to lever arms 93 rigidly connected to flap 88 and 89. These lever arms extending from opposite sides of rudder section 86. Where desired, as shown in FIG. 8, the angularity of relative rotation between flap 88 and rudder 86 may be increased by mounting a pintle 94 on nozzle plate 72, mounting a pintle pin 95 rigidly to flap 88 for rotation about shaft 90 and slidably connecting the shank of pintle pin 95 with a transverse opening in pintle 94. The normal or neutral position of rudder 86 and flaps 88 and 89 is one of alignment with the assembly toeing out at its forward end. The are of rotation of rudder section 86 to hard down positions is shown as 35 in opposite directions from neutral position. The maximum angular movement in rudder section 86 of 35 produces angular movements relative thereto of 24 in the forward flap and 15 in the aft flap.

FIGS. and 11 show further modifications of the three piece articulated rudders wherein the flanking rudders include a modification of the rudder flap control of FIG. 1 and the stern rudder includes a modification of the stern rudder flap control of FIG. 8. The assembly includes a tunnel or nozzle 100 having side walls 101, bottom plate 102, propeller 103 disposed between side walls 101, a propeller shaft 104 extending forwardly of the nozzle and an articulated flanking rudder forward of the nozzle on opposite sides of the propeller shaft. The flanking rudder 105 is mounted intermediate its ends on rudder post 106 for concurrent rotation therewith. At opposite ends of rudder 105 are the forward flap 107 pivotally connected thereto by shaft 108 and rear flap 109 pivotally connected thereto by shaft 110. A member 111 is disposed between the bottom of rudder 105 and nozzle plate 102. One end of member 111 is rigidly connected to flap 109 and the opposite end is slidably and pivotally connected to the nozzle bottom plate by pin 112 having a rectangular head 113 mounted within slotted opening 114 of member 111. Pin 112 has an enlarged bottom portion 115 pivotally mounted in nozzle bottom plate 102. Pin portion 115 has a transverse opening therein through which slidably extends the shank 116 of pintle pin 117 rigidly connected to flap 107. The intermediate portion of member 111 has an arcuate opening 118 through which extends the bottom portion 119 of rudder post 106.

The stern rudder of FIGS. 10 and 11 is also a three piece articulated member comprising the rudder portion 121 mounted 'on rudder post 122 for concurrent rotation therewith, an intermediate flap 1'23 pivotally mounted at one end on rudder post 122 for movement relative thereto and at the other end pivotally connected to rudder flap 124 by means of shaft 125. In normal position the rudder portions 121, 123 and 1324 form a straight rudder extending aft from adjacent propeller 103. The rudder flaps 123 and 124 are controlled from rudder 121 by means of rearwardly extension 126 of rudder 121 disposed beneath flap 123 and pivotally connected to one end of pintle pin 127. Pintle pin 1 27 is mounted on the shank of pintle 128 provided at one end with a head portion 129 pivotally connected by pin 130 to nozzle plate 102 and :at the opposite end 131 slidably connected to shaft 125 within the bifurcated extension 132 of flap 124.

The control and operation of the flanking rudders as shown in FIGS. 1 to 7 inclusive are substantially identical :-except for the ditferences in the flap control rn'ecl'iarlisin shown "in ;the respective figuresl The rudder steering posts of the flanking and steering rudders are each-connected to suitable steering engines so that the arc 'of rotation of the body portions of the flanking rudders and stern rudders ,in either direction from neutral position are substantially equal and the body portions'of the flanking rudders move at all times in substantially parallel relation. It will be noted that in those cases where the articulated flap is on the forward edge of the flanking rudder, each trailing edge of the respective flanking rudders in movement in one direction from neutral position advances to adjacent the side wall ofthepropeller tunnel or nozzle on the nozzle bottom wall in spaced relation to thepivotal connection of the associated steering post, the articulated flap in addition to concurrent rotation with the rudder has a movement of rotation relative to the rudder.

As shown in FIGS. 2, 3, 5 and 6 of the drawings when the respective flanking rudder is in hard down position to either side of its neutral position the articulated flap at its leading edge is disposed at an angle to the body j portion of the rudder thereby providing a greater resistance to and deflection of the water flowing from the reversed propeller and better maneuverability to the boat. The degree of deflection of the articulated flap is a function of the spacing between the pivotal connection of the steering post for the rudder to the tunnel bottom wall and the pivotal connection of the articulated flap control member to the bottom wall. Therefore, the degree of deflection is a matter of design. The degree of deflection in FIGS. 2 and 3 of the drawings is approximately 26. It will be noted as shown in full lines of FIGS. 1 to 3 inclusive, the articulated flap is in alignment with the body portion of the flanking rudder when the rudder is in neutral position. The steering action of the flanking rudder of FIG. 1 of the drawings is substantially the same as that described for FIGS. 2 and 3 with the exception that the articulated flap in FIG. 1 is at the trailing edge of the flanking rudder and hence in hard down position the trailing edge does not move into proximity with the nozzle side wall as in FIGS. 2 and 3. .This however is compensated for by the deflection of the articulated flap whereby the water flowing from the reversed propeller is suitably controlled to increase the maneuverability of the boat. 1

Several forms of control mechanism for the articulated flap have been shown in FIGS 1 to 3 inclusive and it is to be understood that other flap control mechanisms may be substituted for those shown in the drawings without departing from the broader aspects of the invention pertaining to an articulated flanking rudder. In FIGS. 2 and 3 of the drawings the steering rudder has been shown with an articulated flap at the trailing edge and having a flap control mechanism similar to the flap control mechanisms of the flanking rudders.

In FIGS. 8 and 9 of the drawings, the articulated flanking and steering rudders are comprised of three portions. The flanking rudder portion 86 moves concurrently with rudder post 87. Link 91 also rotates concurrently with post 87. The rudder 86 preferably is rotated 35 in either direction to hard down position. Pintle 95 being pivotally mounted on shaft has one end moving concurrently with rudder 86 and its opposite rotating with and slidably moving relative to pintle pin 94 pivotally mounted on nozzle plate 72 forward of post 87. The diflerence between'the radii of rotation of rudder 86 and pintle causes flap 88 to rotate relative to the adjacent end of rudder 86. By reason of lever 93 being rigid with flap 88 and pivotally connected with link 91, the latter moves towards rudder post 87 during .rotates towards the right from normal position. sliding movement of link 91 imparts movement through rotation of'rudder 86 to the'left of normal position and moves outwardly from rudder post 87 when rudderlgg lever 93 at the aft end of the rudder causing flap 89 to rotate relative thereto. As shown on FIG. 8 the net result of sliding and rotating movement of link 91 is to cause the aft flap 89 to rotate about 15 relative to the .adjacent end of rudder 86 and the forward flap 88 to rotate 24' relative to its adjacent endof rudder 86. It will be apparent therefore that any desired rotation of the flaps 88 and 89 relative to rudder 86 may be obtained by suitably varying the location of the pivotal support for pintle pin 94 and/or varying the etfective lengths of link- 91 and levers 93.

The articulated stern rudder has the portion 75 mounted on rudder post 76 for concurrent rotation therewith. The aft rudder flap 78 is actuated by an integral extension 80 of rudder portion 75 disposed beneath rudder portion 77 and pivotally connected at 84 to a lever 85 rigidly connected with pin 81pivotally mounted in nozzle plate 72. The pin 81 being actuated by said rudder extension 80 moves pintle 82 rigidly connected to flap 78. Pintle 82 is slidably mounted in pin 81. When rudder portion 75 is rotated by rudder post 76, the extension 80 having a .longer radius of rotation than lever 85 causes flaps 77 and 78 to move relative to rudder 75. Thus an angular movement of 17 to hard down position in the forward edge of rudder 75 causes an angular movement of 27 in flap 77 :and causes flap 78 to move 23 relative to flap 77. An articulated rudder of such construction imposes greater resistance to the water than in the case of a straight rudder.

Referring now to FIGS. and 11 of the drawings the articulated stern and flanking rudders are of three piece construction. The intermediate flanking rudder section 105 is mounted on rudder post 106 for concurrent rotation therewith. The flap sections 107 and 109 being pivotally connected with section 105 by shafts 108 and 110 respectively, rotate concurrently therewith. Rear flap 109 has member 111 rigidly connected thereto and this member is pivotally mounted intermediate its ends on the rudder post extension 119 within the arcuate slotted opening 118. The forward end of member 111 has a slotted opening 114 receiving the head 113 of pin 112.

.Rotation of rudder portion 105 acting through member 111 causes flap 109 to move relative to rudder portion 105. The pintle 117 secured to flap 107 being pivotally and slidably mounted on nozzle bottom plate 102 forwardly of rudder post 106 causes relative rotation between rudder section 105 and flap 107. As shown in FIG. 10 when rudder section 105 is in hard over position of 35 from normal or inoperative position, the rear flap 109 has rotated relative thereto about 12 and the front flap 107 has a relative rotation of about 24. These angles of relative rotation of the flaps 107 and 109 can be varied by changing the length of member 111 and pivotal support for pintle 117.

The three piece stern rudder is controlled by the rudder section 121 mounted on rudder post 122 for concurrent rotation therewith. The rear flap 124 is controlled by rudder section 121 acting through its extension 126 having a pivotal connection with 128 through pin 127 to cause member 128 to pivot on pin 130. These forces acting on flap 124 causes intermediate flap 123 to rotate 27 from straight rudder position when rudder section 121 is rotated about 17 and causes rear flap 124 to rotate about 23 relative to intermediate flap 123. In other words angular movement in rear flap 124, from straight rudder position, of 50 to hard over rudder position requires about 17 rotation of rudder post 122 and rudder section 121.

The exact details of construction as shown in the drawings are for purposes of illustration and not limitation except as made necessary by the scope of the appended claims.

I claim:

1. In a rudder control system for boats having a propeller disposed within a tunnel provided with side walls disposed on opposite sides of the propeller and connected by a bottom wall extending forwardly of the propeller and tunnel side walls, the combination of, flanking rudders mounted adjacent opposite sides of the propeller and pivotally connected intermediate their ends with the tunnel bottom wall, the aft end of each rudder extending between the tunnel side walls, an articulated end portion on each rudder and aligned therewith when the rudder is in neutral position, a pintle pin rigidly connected with said articulated rudder portion and extending therefrom, a pintle mounted on the tunnel bottom wall and an opening extending transversely of the pintle for slidably receiving the extending end of the pintle pin.

2. The rudder control system as in claim 1 wherein, the tunnel bottom wall is extended aft of the propeller, a steering rudder is pivotally mounted at one end to the said bottom wall in alignment with the propeller, the steering rudder intermediate its ends is articulated, and a pintle pin control is provided for the articulated end portion of the steering rudder as is provided for the flanking rudders.

3. In a rudder control system for boats having a tunnel, a bottom wall on said tunnel, a propeller disposed within the tunnel, and driven by a longitudinally extending shaft, a pair of flanking rudders disposed forwardly of the tunnel on opposite sides of the propeller shaft within the flow of water from said tunnel when the propeller is rotated in a reverse direction, and a stern steering rudder disposed rearwardly of the propeller, each of said rudders comprising a plurality of pivotally connected sections, one section of each said rudders being rigidly connected with an adjacent rudder post for concurrent rotation therewith, and means connecting the remaining sections of each said rudder with the first named section of the rudder and with said tunnel bottom wall for effecting bodily movement of said remaining sections with the rudder post mounted section and pivotal movement relative to the rudder post mounted section.

4. In a rudder control system for boats of the character described having a tunnel provided with side and bottom walls and a propeller mounted between said walls, the combination of a pair of flanking rudders disposed forwardly of the propeller and between said tunnel walls, each said rudder comprising a plurality of vertically disposed pivotally connected sections, a steering post associated with each rudder and having a pivotal connection with the tunnel bottom wall, one of said rudder sections being connected to the post for rotation therewith, a rudder and section pivotally connected to each end of the post mounted section, a lever member secured to each rudder end section, a link connecting said lever members and slidably connected with the steering post, a pintle pivotally mounted on the tunnel bottom wall, a pintle pin secured to one rudder end section and having a sliding pivotal connection with said pintle pin.

5. In a rudder control system for boats of the character described having a tunnel provided with side and bottom walls and a propeller mounted between said walls, the combination of a pair of flanking rudders disposed forwardly of the propeller and between said tunnel walls, each said rudder comprising a plurality of vertically disposed pivotally connected sections, a steering post associated with each rudder and having a pivotal connection with the tunnel bottom wall, one of said rudder sections being connected to the post for rotation therewith, a rudder section disposed at each end of the post mounted section, a member disposed beneath the center rudder section, one end of said member being secured to an adjacent rudder end section, a slotted pivotal connection between the rudder post and member intermediate the ends of the latter, a pintle pin mounted on the tunnel bottom plate adjacent the other rudder end section, a pintle mounted on the adjacent rudder end section, a sliding pivotal connection between the pintle and pintle pin, and a sliding pivotal connection between said pintle pin and the adjacent end of the aforementioned member.

6. In a rudder control system for boats, in combination, a propeller tunnel, a screw propeller mounted within the tunnel, a bottom wall on the tunnel extending forwardly and aft of the propeller, a stern rudder disposed rearwardly of the propeller and pivotally connected with said tunnel bottom wall, a pair of flanking rudders disposed forwardly of the propeller and adjacent opposite sides thereof within the flow of water from said nozzle when the propeller is rotating in a reversed direction, each said flanking rudder having a pivotal connection intermediate its ends with said bottom wall, a flap pivotally mounted on one end of each flanking rudder for concurrent rotation therewith, and means mounted on said tunnel bottom wall and connected with said flap pivotal mounting on said flanking rudder providing relative pivotal movement between the flap and flanking rudder as the flanking rudder rotates relative to the bottom wall.

7. In a rudder control system for boats, in combination, a nozzle, a shaft driven propeller disposed within said nozzle with the shaft thereof extending forwardly therefrom for moving the boat in forward and reversedirections, a steering rudder disposed in rearward alignment with the propeller, a bottom wall on said nozzle having extensions fore and aft of said nozzle, a flanking rudder pivotally mounted intermediate its ends upon said nozzle wall extension forwardly of said propeller at each side of the propeller shaft, said flanking rudders being disposed within the flow of water from said nozzle when the propeller is rotated in a reversed direction, an articulated rudder portion pivotally mounted on an end of each flanking rudder and normally extending in alignment therewith when the flanking rudder is in non-operative position during forward movement of the boat, and means connecting said articulated rudder portion with said nozzle bottom wall for disposing the said end rudder portion in angular relation to said flanking rudder during actuation of said flanking rudder.

8. In a rudder control system for boats, in combination, a propeller tunnel having side walls and a bottom wall extending beyond the side walls, a rudder having a body portion pivotally mounted on the boat and having a pivotal connection with said bottom wall, an outer end portion on said rudder having a pivotal connection with the main body portion of said rudder for pivotal movement relative thereto, a member disposed transversely of the rudder end portion and fixed relative thereto about a pivotal connection with the body rudder portion, a shaft member pivotally mounted on the tunnel bottom wall in spaced relation to the rudder bottom portion pivot, a transversely extending opening in the shaft member, a pintle pin slidably mounted in said shaft opening and extending therefrom toward said rudder end portion, a head portion on said pin extending transversely of the end thereof, spaced link members pivotally connecting said transversely disposed rudder end portion member and pintle head portion, said link members being actuated by movement of the rudder body portion to efiect relative movement between the rudder end portion and rudder body portion concurrent with movement of the rudder body and end portions about the rudder pivot.

9. In a rudder control system for boats, in combination, a nozzle having a bottom wall providing extensions thereof fore and aft of said nozzle, a screw propeller within said nozzle and having a driving shaft extending forwardly therefrom, a flanking rudder disposed at each side of said shaft and forwardly of said propeller within the flow of water from said nozzle when the propeller is rotating in a reversed direction, a pivotal support and turning means intermediate the ends of each flanking rudder mounted on said bottom wall extensions, each said flanking rudders having at least one end thereof provided with a flap pivotally mounted on the flanking rudder for concurrent rotation therewith, and means having one end mounted on said flap and the opposite end mounted on the adjacent said nozzle bottom wall extensions, said means being actuated by rotation of the flanking rudder to provide concurrent rotation of the flap and flanking rudder, and relative pivotal movement between the flanking rudder and flap.

10. The rudder control system as defined in claim 9 wherein the stern and flanking rudders each have a flap pivotally connected to one end of the respective rudders, means mounted on the said bottom wall beneath each said rudder, and a connection between each said means and its adjacent flap at the pivotal mounting thereof on the rudder causing relative rotation between its associated flap and the rudder as the rudder rotates relative to the said bottom wall.

11. The rudder control system as defined in claim 9 wherein the connection between said means and bottom wall is a pivotal connection.

12. The rudder control system as defined in claim 11 wherein the connection between said means and bottom wall provides relative movement between the means and wall longitudinally of said means.

References Cited in the file of this patent UNITED STATES PATENTS 1,100,349 Brennan June 16, 1914 1,382,170 Conti June 21, 1921 1,717,286 Ward June 11, 1929 1,745,370 Howard Feb. 4, 1930 2,030,375 Kort Feb. 11, 1936 2,201,859 Edwards May 21, 1940 2,251,133 Horstman July 29, 1941 2,784,691 MacMillan Mar. 12, 1957 2,812,738 Munro Nov. 12, 1957 FOREIGN PATENTS 9,433 Sweden Dec. 10, 1898 18,366 Germany June 12, 1882 572,422 Germany Mar. 16, 1933 OTHER REFERENCES The Kort Nozzle, published by the Kort Co., Inc., 17 Battery Place, New York, dated printed thereon0ctoher 1935.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,996,031 August 15, 1961 I I Elmer W. Easter It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as "corrected below.

Column 8, line 54 for "and" read end Signed and sealed this 19th day of December-1961.,

' (SEA L) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer v Commissioner of Patents USCOMM-DC 

